Paul giraud



2 Sheets-Sheet 1.

(No Model.) I

P. GIRA THBRMO BLEG-TRI ented Odt, 4, 1892.

(No Model.) 2 SheetsSheet 2.

vP. GIRAUD. THERMO, ELECTRIC BATTERY.

Iva 483,782. Patented Oct 4, 1892.

UNITED STATES PATENT OFFICE.

PAiU-L GIRAUD, or 'CI'IAfN-TILL Y, FRANCE.

THERMO-ELEGTRIC BATTERY.

SPECIFICATION forming part of Letters Patent No. 483,782, dated October4, 1892. Application filed August 1,1891. Serial No. 401,378- (Nomodel.) latented in France April 10, 18 90, No. 204,902.

To all whom it may concern:

Be it known that 1, PAUL GIRAUD, of Chantilly, in the Department ofOise, in the Re public of France, have invented a new and usefulImprovement in Thermo-Electric Batteries, (for which I have obtainedpatent in France, No. 204,902, dated April 10, 1890,) of

which the following is a specification.

I will describe my invention with reference to the drawings andafterward point out its novelty in claims.

Figures 1 and 2 of the drawings represent, respectively, a side view anda plan of one element of a battery constructed according to myinvention. Fig. 3 representsa horizontal section of a group of elementsconnected. Fig. 4 represents a vertical section, in the line A B of Fig.3,0f several superposed elements. Fig. 5 is an end view correspondingwith Figs. 3 and 4. Fig. 6 is a detail view-illustrating the connectionsbetween the elements. Fig. 7 represents a vertical section of a portablestove, serving for the heating-of one of the extremities of Fig. 8represents a horizontal section on a larger scale than Fig. 7, taken inthe line Y Z of the latter figure. Fig. cal section of'a modification ofthe stove shown in Figs. 7 and 8.

Each element of the battery is composed of an electrode a and anelectrode 1) b, the eleca trode a. being a casting of one of such alloysas are herein specified and the electrode b b consisting of two platesof sheet metal. The elements are formed by placing one end of a plate band one end of a plate I), one in one end and the other in the oppositeend of the mold in which the electrode a is to be cast, and afterwardcasting the latter electrode in-said mold upon the said ends of saidplates. The electrodes (1. are formed of alloy of zinc, anti: lnony,copper, tin, silicium, and cadmium. Certain of these metals-such as zincand antimony-have already been used in thermoelectric batteries; but myexperience has led me to employ them in various practical conditions,from which results, first, that they" furnish a greater electro-motiveforce without increasing the internal resistance of the element, and,second, that I avoid the primitive crystallization (thoseresultingimmediately from casting) as well as the ulterior crystal thethermo-electric electrodes.

.9 represents a verti-- lizations (those produced by the heating ofthe'elements.) The solidity and durability of the elements are thusincreased. As to copper, I add it, 'first, to augment the mechanicalresistance of the alloy; second, to diminish its internal electricresistance, and, third, to raise the fusion-point of. the alloy. On theother hand, the tin which enters into the composition. of my alloy makesit flow better for casting and renders it more homo.- geneous and moresolid. The siliciuln increases the resistance to breakage.- Finally, thecadmium, which I employ in convenient proportions with other metalsabove mentioned, has for its object to greatlyaugment the electro-motiveforce of its elements.

I give as follows the three compositions which I at present employ inthe manufacture of the elements:

Composition A for elements of small size; Antimony, 1,450 parts, byweight; -zinc, 900 parts, by weight; cadmium, 50 parts, by weight; purecopper, 80 parts, by weight; tin, 40 parts, by weight; silicium, 3parts, by weight.

Composition B for elements of medium size: Antimony, 1,440 parts, byweight; zinc, 780 parts, by weight; cadmium, parts, by weight; purecopper, 30 parts, by weight;ti-n, 15 parts, 'by weight; silicium, 2parts, by weight.

Composition 0 for elements of large size: Antimony, 1,830 parts, byweight; zinc, 960 parts, by weight; cadmium, parts, by weight; silicium,2 parts, by weight.

As I have shown,there may be notably differences between the proportionsof the different metals; also, that the copper and tinmay be omitted(composition C) when the ele ments by reason of theirlarge size presentsufficient'guarantee 0t solidity. I might even depart to a, certaindegree from the proportions indicated in the above table. Theproportions in which the d'ifierent metals enter into the alloy mayvary, in fact, according to the greater or lessefiect which it isdesired to have and the dimensions of the elements. My experiments haveproved to me that the composition of the alloy being the same theelectro-motive force of an element varies, first, with the threedimensions given to the elewent; and second, with the thickness(vertical dimension) of the element, the length and. breadth not being,changed. Thus, for ex ample, with the same metallic composition thesamelength and the same breadth an element of two centimeters thickness willhave a greater electro-motive force than another of three or fivecentimeters thickness. The longitudinal electric resistance will also begreater in the former than in the latter.

The changing of the proportions of the alloy has for its end to preserveto the elements, while increasing its thickness, the same electro-motiveforce, and that without increasing its internal electric resistance. Theeffect is thus greatly augmented.

Three thicknesses of electrodes a, which may be employed with thegreatest advan: tags, are asjfollows, according to different cases:

Small size, length equals .07 millimeter,

breadth equals .02 millimeter, and height' equals .02 millimeter; mediumsize, length equals .07 millimeter, breadth equals .02 millimetergandheight equalst03 millimeter; large size, length equals .10 millimeter,breadth equals ,08 millimeter, and height equals .05 nilliineter.

These proportions may evidently varyin a certain degree.

As I have above explained, I modify the composition of the alloyaccording to the dimension of the electrode.

The second electrode b or b of each element is preferably constituted oftin-plate or of a plate of pure nickel; but the said electrodes may alsobe made of sheet-iron havingits surface coated with iridium, platinum,or nickel, or made of form-aluminium. Each of the plates 1) b,constituting electrodes, is united with the electrode a by anautoge-neous solderthat is'to say, produced by the casting of the alloyforming the latter electrode.

In order to have a perfect unionand a large surface of contacts, (whichit is evident is of greati1np0rtance,) the extremity of each plate isfirst divided by several longitudinal slits. Thenthe tonguesthus formedare turned alternately to the right and left and afterward twisted, asmay be clearly seen in-Figs. 2, 3, 4, and 0, to anchor the said platesinto the electrodes a. The part of the plate b which is next the innerend of the electrode ais folded over against that end, then again foldedto be applied against the lateral face of the said electrode a, athickness of amianthus or other insulating material being interposedbetween the last-mentioned face and the said plate. The plates 1) and bof two adjacent elements are lapped and secured together by a solderwhich will not melt at the temperature to which it has to be exposed.This mode of connection permits the easy replacement of one of theelements in case of damage by unsoldering the two joints between thatand the adjacent elements in the same row, and replacing the damagedelement by a good one serving both for Warming the of an apart ment orof any space whatever,"and produc ing electricity for lighting or [otherpurposes.

Figs. 7, 8, and 9 show this application offiny elements. around astove,wl1ich constitutes an important feature of my invention. heresupposed the employment of a stove of a portable kind which may berolled about from one part of an apartment to another. The employment ofthe stove in this way as a generator of heat permits me to utilize forthe heating of the battery 'all the heat commonly lost from the stove,whence results a perfect utilization of the combustible earpended, and

consequently great economy. This utilization is more perfect when 1cmploy a stove so constructed that the-outersurface is never above amoderate heat, as it is always desirable that the stove shall be suchthat the solderings of the elements should not be heated to a sufficienttemperature to melt them. In my system the thermo-electric batterysurrounds the stove exteriorl y, the solderings, which should bemaintained cold, being toward the exterior and being cooled by a currentof air, for example, while those so]- derings which must be heated aretoward the interior and exposed to the heating actio of the stove. Theelements of the battery are not in contact either with the combustibleor the gases of combustiomnor even directly with the walls of theheating apparatus, and this, in connection with the special arrangementof the elements, prevents all deterioration and insures the battery analmostindefinite durability.

The stove represented is composed of two distinct parts-via, the stove,properly so called, and a jacketg,whichsurrounds it,w'ith a space Ebetween them to contain. the thermoelectric battery. The whole restsupon a base Z, preferably mounted upon" wheels 'It, which permit theapparatus to be moved about.

I will now describe that example of the stove proper represented inFigs. 7 and S: 'i is aconica1cast-iron fire-pot, of which the bottom isconstituted by the movable grate j, which rests upon a cast-ironcylindrical piece 7r, car ried by the base I. on is a hollow cylinder ofcast-iron, situated above the said pot and, serving, with the said pot,to contain the i iicandescent fuel, and or is a slightly-conicalfuel-reservoir situated above the said cylin- 1 have" IIO der m. Thesaid cylinder m is of a diameter somewhat smaller than that of thebottom of the fire-pot, so that there is an annular opening 1) betweenthem interrupted only under the mouth 0 of the smoke-pipe, where thereis a horizontal flange n, which rests upon the top of the pot. The saidcylinderm has upon its exterior a series of vertical radial ribs m, theouter edges of which fit to the external cylinder e, which constitutesthe exterior wall of the stove 'proper. This cylinder e and the jacket Bboth rest on a a gallery is, provided on the exterior of the lowercylindrical piece is on the base Z. At the top of the cylinder e,reservoir 'n, and jacket q, which are all car ried up to the sameheight, there is an annular cap-plate s, which covers the space betweenthe cylinder e and the reservoir, and that B between the said cylinderand the jacket q, and in this cap-plate is provided an annularsand-channel for the reception of the edges of the covers of thereservoir 71, which cover is removable for charging'the reservoir withfuel. The cap-plate is also provided with a larger removable cover 8which also covers the annular space provided between the exterior e ofthe stove proper and the jacket q to receive the battery. This largercover is of spider form to permit the escape of air and heat from thesaid annular space.

In the above-described example of my invention gases of combustion passfrom the fuel in the pot 'i and the lower part of the cylinder m throughthe opening '0' and circulate within the space between the exteriors ofthe.

cylinder m and reservoir c and the interior of the cylinder 6 and passout by the smoke-pipe 0 to the atmosphere, the circulation, first upwardand then downward, being produced by the ribs m and flange n.

The gallery is, hereinbefore mentioned as surrounding the cylindricalpiece It and as supporting the cylinder and jacket q, also supports thebattery elements. This gallery has in it numerous holes '1' for theadmission of air to the annular space B between the said cylinder andjacket, and the cap-plate s has in it numerous small holes for theescape of air from said space. The extremity of each electrode a whichis intended to be heated is first plunged into a plaster made ofpulverized amianthus and silicate of soda or silicate of potash,preferably silicate of soda, and is then inserted into a little cup 0,which may be made by stamping out of sheet metal. This cup serves notonly to prevent the'metal of the electrode from fusing externally, butalso to spread the heat equally around the-sides of the end which is tobe heated. The plaster of silicate of soda or silicate of potash andamianthus (indicated by (Z in Figs. 3, 4 and 5,) contributes to assurethe electric insulation at the same time that it produces the adhesionof the electrode to its cup 0.

The cups 0, electrically insulated. from the external wall or cylinder eof the stove by a sheet of amianthus paper f, are cemented to said wallor cylinder by means of the plaster of silicate and amianthus,hereinabove mentioned. The diifere thorizontal tiers of cups 7e 0 areinsulated one rom another by rings or washers of amianthus paper g, (seeFigs. 4, 5,

and 6,) and between the vertical faces of the said cups of the samehorizontal tier there are also interposed small pieces of amianthuspaperh. I may employ any other insulating ma. teri-al; but the amianthuspaper gives very good results. Imay, for instance, employ mineral'wool.The cups may be afiixed to the cylinder e by any'other suitable adhesivecement. 8c

left around each element, finally escaping after having been heatedthrough the holes in the cover 8. This circulation of air takes placeover all the surfaces of the portions of the elements which requires tobe cooled, in-

cluding the vertical exterior face, because there is a certain amountofspace left between this space and the jacket q. To favor the cooling,this jacket is blackened inside and outside.

With the construction of stove which I have just described and which isrepresented in Figs. 7 and 8 the gases of combustion pass more or lessdirectly to the chimney. It results therefrom that the higher portionsof the battery are less heated than the lower portions and furnish acurrent less intense than the latter. The utilization of the combustiblewill then be better and the electric result be augmented if the gasesremain. a long time 'within the space between the reservoir n and thecylinder e and are obliged to rise to the upper part of the stove. Thisefiect may be obtained by interposing between the reser* voir n andcylinder e an additional cylinder 0, serving as a baflie. In thisconstruction, which is'represented in Fig. 9 of the draw ings, the gasesof combustion, arriving at the exterior of the winged cylinder m, risebetween the reservoir 'n and the additional cylinder 1), which may bemade of sheetiron or cast-iron, passing through orifices v in the upperpart of the said cylinder, descending through the space between thecylinders 'v and e, and escaping by the smoke-pipe 0 after having lostthe greater part of their heat.' In this example the horizontal flangen'of the winged cylinder m, as shown-in Fig. 7, must evidently s orcoal-I may also employ a liquid or gaseous combustible.

The stove represented in the drawings may be heated by gas or otherhydrocarbon liquid by simply taking out the grate and introducing in itsplace suitable combustion apparatus.

. What Iclaim as my invention,and desire to secure by Letters Patent,is-- '1. An electrode'for a thermo-electric batt'ery, composed ofantimony, zinc, cadmium,

and silicium in proportions substantially as.

herein set forth,

- 2. An electrode for a thermoelectric battery, composed of antimony,zinc, cadmium, silioium, copper, and tin in proportions substantially asherein set forth.

3. The combination, witheach battery element and the heating-surface towhich it is attached, of a metal cup 0, receiving the inner end of saidelement and insulated therefrom 'by a cement which serves to hold theelements in the cop, the said cup serving" to attach the elements to theheating-surface and to trans mit heat uniformly around that end of theelement which is to be heated, substantially as herein. described,

4. The combination, with aheating-surface and a series ofthermoelectric-battery elements arranged in several tiers against suchsurface, of a series of metal cups 0, receiving and. insulated fromtheir respective elements and each insulated from the adjacent ones of'the same tier and from those of the tiers above and below and beingsecured to said heatingsurface by an insulating cement, substantially asherein set forth. 5. The combination, with the co'mbustiom chamber andthe series of thermoelectric elements with which it is surrounded, ofthree annular walls n v e, arranged one within another between saidchamber-and said series of elements and forming two annular spaces, theinner of which spaces communicates at its lower part with thecombustionchamber and the outer of which spaces has an outlet in thelower part to the atmosphere. and the middle wall 1), having openings inthe upper part, and the thermoelectric elements being outside ofand-attached to butinsulated from the outermost of said walls c, allsubstantially as herein set forth.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

PAUL GIRAUD.

